Mastitis is an inflammation and infection of the mammary gland that is particularly frequent in women and other mammal females during lactation. Mastitis is mainly caused by staphylococci and/or streptococci selection and overgrowth in the mammary ducts and mammary areola glands. Human mastitis affects up to 30% of lactating women and often leads to a precocious and undesired weaning because it is a really painful condition.
Moreover, mastitis is not human-specific pathology but affects to all mammalian species. In this sense, infectious mastitis in animal species and breeds reared for milk production, such as cows, ewes or goats, is an important economic problem since milk produced during the infective process must be discarded due to the high bacterial and somatic cells counts. In addition, mastitis can be an important problem in those domestic species (pigs, rabbits . . . ) and breeds (e.g., meat-producing bovine) not dedicated to milk production since a reduced milk supply of low bacteriological quality may notably increase the morbidity and mortality rates among the offspring.
In these cases, antibiotic-based therapy has emerged as the unique therapeutical option. However, current wide-spectrum or Gram positive-targeted antibiotics are poorly effective for the staphylococcal and streptococcal strains causing mastitis and, in fact, such treatments can be in some circumstances, detrimental because they usually eliminate the commensal flora that characterise mammal milk, which could exert some protective effects. Moreover, antibiotic therapy may result in the appearance of antibiotic residues in the milk, which is also detrimental if occurring during the lactating period. Alternatively, recombinant bovine GM-CSF has also been used for the treatment of subclinical mastitis caused by S. aureus (Takahashi, H. et al. 2004, Cad. J. Vet. Res. 68:182-187) but did not prove efficient in the treatment of late-stage S. aureus infection.
An alternative approach for the treatment of mastitis is the use of probiotics. For instance, Sytnik, S. I. et al. (Vrach Delo., 1990, 3:98-100) attempted to use Bifidobacteriumi for preventing mastitis but did not observe any inhibition in the residence time of the breast microflora. Greene, W. A. et al. (J. Dairy Sci., 1991, 74:2976-2981) described the use of a commercial lactobacillus preparation for the treatment of elevated somatic cell count (SSC) when administered by direct intramammary injection but conclude that the Lactobacillus product used in the assay was not effective as an intramammary treatment of subclinical mastitis based on SCC. The U.S. Pat. No. 4,591,499 describes a method for treating mastitis using an intramammary injection of an oil in water emulsion containing a non-pathogenic lactobacillus strain or a mixture of strains. However, the strains described in this document appear to act by means of a non-specific decrease in the pH in the mammary gland and, due to their particular formulation as emulsions, need to be administered by direct intramammary injection. The Russian patent RU2134583 describes the use of topic composition containing lactobacterin (microbe mass of lactobacteria that have been live lyophilized/dried in culture medium) or bifidumbacterin (a lyophilised biopreparation immobilized on special activated charcoal) for the treatment of massive microbe dissemination of breast milk. However, this preparation is only suitable for the topic administration and forms part of a multi-step treatment that includes relaxation massage and application of a suspension of organisms derived from the normal microflora of the intestine additionally containing a protective film-forming medium. The international patent application WO05/34970 describes the treatment of mastitis by direct intramammary injection of a Lactococcus lactis strain.
Therefore, all the prior art described above relate to the use of probiotic strains by either intramammary injection or topical application. Thus, there is a desire in the art for additional approaches to allow the prevention and treatment of mastitis and other mammary gland pathologies, in women and in other mammal females, which can be more easily applied and by less invasive means.